1. Field of Invention
The present invention relates to sliding wheels arrangement for a curtain, and more particularly to a sliding wheel slidably suspending a curtain cloth, wherein each of the sliding wheels has an enhanced supporting structure for slidably supporting the curtain thereby.
2. Description of Related Arts
Window curtains are used in buildings mainly for shielding sunlight and to create privacy for people. They are also used for decoration especially for home. A window curtain usually comprises a curtain cloth for shielding sunlight and a sliding mechanism which suspends the curtain cloth and is also capable for sliding along a gliding track for opening and closing of window curtains.
The present invention relates to the sliding wheel of the window curtain. A conventional sliding wheel usually comprises a sliding hanger having a hanging arm to suspend the curtain cloth, a sliding support having a pair of wheel seating jointed together by ultrasonic welding and a plurality of sliding elements installed within to enhance the sliding ability.
Regarding to such conventional sliding wheel, some drawbacks can be found. First, the pair of wheel seating jointed by ultrasonic welding requires extra labor cost. It is often not repairable or replaceable with a single part. The whole wheel seating unit is usually replaced when the unit is damaged. Thus, welding the pair of wheel seating together permanently is not practical in the sense of manufacturing and liability.
Second, the conventional two pieces joint wheel seating may not be secure enough for supporting various kinds of stress from a wide variety of circumstances. For examples, U.S. Pat. No. 6,189,182 discloses a guiding block for pulling a window curtain. The sliding support here in this patent is jointed by a left wheel seat and a right wheel seat with a locking mechanism. The left wheel seat has a left spacer with a through hole on the center thereof as the primary body itself and a convex tube extended from one side and a rib is installed inside the convex tube. The right wheel seat has a right spacer with a through hole on the center thereof as the primary body itself and a convex tube that is extended from one side for insertion and a notch that is longitudinally installed with the convex tube and a circular groove is installed on the outside of the convex tube. The two wheel seats are then jointed together when the right wheel seat is inserted into the left wheel seat where the convex tube of the right wheel seat is enforced through the rib of the left wheel seat. The faces of the rib and the convex tube of the left wheel seat couple with the faces of circular groove and the right spacer of the right wheel seat respectively so that the two wheel seats are locked together. In the case here, the main disadvantage is that there is insufficient support for the wheel seats especially when the sliding wheel is experiencing abnormal stresses. The reason is because both the wheel seats are hollow in center and the hollow convex tubes do not provide enough support when they go under heavy or sudden loading. The existence of the notch of the right wheel seat also decreases the strength of the structure. Another disadvantage of this design is that if one of the wheel seats breaks, then it is required to replace the whole wheel seat.